The present invention relates to an adjusting and support apparatus for an automotive lamp unit such as a headlight, foglight, etc., and more particularly to one having a separate adjusting and support structure.
Conventional adjusting and support apparatus for automotive lamp units include three supports: one horizontal adjusting screw, one vertical adjusting screw, and one pivot. All three of the supports are weight-bearing in that they bear the weight of the lamp unit while supporting it within a support frame attached to the automotive vehicle. In addition to supporting the lamp unit within the support frame, the horizontal and vertical adjusting screws also serve the function of providing means for adjusting the positioning of the lamp unit, in relation to the support frame, about a vertical and horizontal axis of adjustment, respectfully, of the lamp unit. In this manner, the direction of a light beam emanating from the lamp unit can be adjusted in a horizontal plane and in a vertical plane to achieve a desired direction of aim.
Generally, the horizontal and vertical adjusting screws support the lamp unit in a cantilevered relationship where one end of the screw is attached to the support frame while the other end is attached to the lamp unit. By axially rotating the screw, the point at which the screw is attached to the lamp unit is either moved towards or away from the support frame, .depending on the direction of rotation. When the horizontal adjusting screw is thus rotated, the lamp pivots about the vertical adjusting screw and the pivot. Together, the vertical adjusting screw and pivot define the vertical axis of adjustment. In a similar fashion, when the vertical adjusting screw is axially rotated, the lamp unit pivots about its horizontal axis of adjustment, which is defined by the horizontal adjusting screw and the pivot.
An example of such a conventional adjust and support apparatus for an automotive lamp unit is disclosed in Iwamoto, U.S. Pat. No. 4,870,544. A headlight unit is supported within the body of a motor vehicle by a pivot assembly pivotally connected to one corner of the headlight unit, and a pair of holder support members fixed to opposing corners of the headlight unit such that the support members and pivot assembly define a right angle, with the pivot assembly located at the corner of the right angle. A threaded rod threadingly connects each of the holder support members with the vehicle, while the pivot assembly is simply fixed to the vehicle. In this manner, the rotation of one of the threaded rods causes the headlight unit to tilt about its vertical axis, while rotation of the other causes the headlight unit to tilt about its horizontal axis.
As mentioned, in such a conventional adjust and support apparatus, the horizontal and vertical adjusting screws provide a dual support and adjusting function via a threaded cantilever attachment of the lamp unit with the vehicle. Such an arrangement is undesirable in that, while the adjusting screws generally provide an effective mechanism by which to adjust the aim of the lamp unit, their dual role as a supporting mechanism is disadvantageous. The cantilevered adjusting screws provide a stiff support structure which tends to transmit, rather than dampen, concussions to the lamp unit caused by vehicle vibrations during travel. Such concussions, over time, may result in the failure of the filament contained within the lamp unit light bulb.
Another disadvantage inherent with conventional automotive lamp unit adjust and support mechanisms is the stringency of the positional relationship in which the pivot, horizontal adjusting screw, and vertical adjusting screw must be placed. Specifically, the pivot, horizontal adjusting screw, and vertical adjusting screw must be: 1) placed in an orthogonal relationship with one another, and 2) attached to the lamp unit in roughly the same vertical plane. These positional requirements are necessary in order to achieve proper horizontal and vertical adjustment of the aim of the lamp unit. However, such constraints limit the flexibility with which the front or grill portion of vehicles can be designed. As is known, space under the hood of the vehicle in the vicinity of the head lamps is limited. In designing a vehicle, efforts are continuously made to maximize the use of such limited space, as well as to design an aesthetically appealing grill portion with excellent fit and finish characteristics. The stringent positional relationship of the pivot, horizontal adjusting screw, and vertical adjusting screw dictated by conventional lamp unit adjust and support mechanisms frustrate such efforts.
Accordingly, it is seen that a need exists in the art for an adjusting and support apparatus for a lamp unit which provides improved support for the lamp unit and which allows greater flexibility in the positioning of the adjusting mechanism.